The inventive subject matter relate to semiconductor devices and manufacturing methods thereof and, more particularly, to three-dimensional semiconductor memory devices and methods of fabricating the same.
Semiconductor devices are becoming more highly integrated in order to provide high performance and low cost. The integration density of semiconductor devices is a factor that may influence the cost of semiconductor devices. An integration degree of a conventional two-dimensional (2D) memory device may be determined by an area that a unit memory cell occupies. Therefore, the integration density of the conventional 2D memory device may be greatly affected by the level of a fine pattern formation technique. However, high-priced equipment may be needed to form fine patterns, thus potentially limiting the integration density of 2D memory devices.
Semiconductor devices including three-dimensionally arranged memory cells (i.e., three-dimensional (3D) memory devices) have been proposed to overcome the above limitations. In 3D memory devices, interconnections (e.g., word lines and bit lines) among cells may be three-dimensionally arranged.